A Millimeter-Wave Dual-Band Multi-Resonator Hybrid Antenna Suitable for Beam Scanning

Abstract

The present invention belongs to the technical field of microwave communication, and particularly relates to a millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning. It includes a first substrate, a second substrate, and a third substrate stacked in sequence from top to bottom; a first rectangular metal patch and n×n metal strips surrounding the first rectangular metal patch are printed on the upper surface of the first substrate; a second rectangular metal patch is printed on the upper surface of the second substrate; a metal ground is provided on the upper surface of the third substrate; a rectangular slit is etched on the metal ground; a microstrip line for feeding is provided on the lower surface of the third substrate; inner metallized vias and outer metallized vias are provided around the antenna; the inner metallized vias penetrate through the second substrate and extend downward to the third substrate to form a substrate integrated waveguide back cavity; the outer metallized vias penetrate through the first substrate and the second substrate and extend downward to the metal ground; the radio frequency excitation signal is fed in by the microstrip line and coupled through the rectangular slit to feed the antenna located thereon.

Description

Technical Field

[0001] The present invention belongs to the technical field of microwave communication, and particularly relates to a millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning. Background Art

[0002] Millimeter-wave technology is a key factor for realizing high-data-rate wireless communication in the fifth-generation mobile communication technology. Currently, the authorized 5G millimeter-wave frequency bands worldwide are n257 (26.5 - 29.5 GHz), n258 (24.25 - 27.5 GHz), n260 (37.0 - 40.0 GHz), and n261 (27.5 - 28.35 GHz). Generally speaking, the n257, n258, and n261 frequency bands are classified as the 28 GHz band, while the n260 frequency band is classified as the 39 GHz band. Dual-band antennas can reduce the number of antennas in the system, simplify the hardware structure, and reduce the cost of the system, which is an ideal solution for covering the above 28 / 39 GHz millimeter-wave frequency bands. According to the spectrum division, it is required that the designed millimeter-wave antenna must have a relatively wide bandwidth within both the 28 GHz and 39 GHz frequency bands. In addition, in order to cope with the path loss generated in the millimeter-wave range, millimeter-wave antennas usually appear in the form of arrays in practical applications. In order to improve the spatial coverage rate of the antenna, the antenna array must have a wide beam scanning angle, which requires the millimeter-wave antenna array spacing to be maintained at about half a wavelength, thereby further requiring that the planar size of the antenna element must be much smaller than half a wavelength. In this context, in the field of antenna technology, it is of great research significance to design a dual-frequency dual-wideband and miniaturized antenna covering millimeter-wave 28 / 39 GHz.

[0003] The currently proposed millimeter-wave dual-band antennas are mainly divided into three categories and have limitations: The first is to achieve dual-band coverage by exciting dual / multiple operating modes in a single resonator. However, due to the limited number of antenna modes in a single radiator (≤ 3 modes), the bandwidth of each frequency band is often too narrow (~5%); the second method is to use multiple resonator structures to achieve dual-band coverage of millimeter waves. However, the existing designs are still limited to two or three resonators, so the number of provided modes is still limited (≤ 3 modes), and wide-band coverage of the two frequency bands cannot be achieved; the third method is to use the first two methods in combination. Although dual-band broadband coverage can be achieved, it often leads to an oversized antenna size and cannot solve the problem of wide-angle beam scanning. Summary of the Invention

[0004] Aiming at the problems existing in the above-mentioned prior art, the present invention proposes a millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning, which solves the problems existing in the design of existing millimeter-wave dual-band antennas, such as narrow antenna bandwidth, large planar size, and difficulty in individually adjusting each frequency band.

[0005] To achieve the above-mentioned invention objectives, the present invention adopts the following technical solutions:

[0006] A millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning includes a first substrate, a second substrate, and a third substrate stacked in sequence from top to bottom. There is an adhesive board between the first substrate and the second substrate, and an adhesive board between the third substrate and the fourth substrate; a first rectangular metal patch and n×n metal strip lines surrounding the first rectangular metal patch are printed on the upper surface of the first substrate; a second rectangular metal patch is printed on the upper surface of the second substrate; a metal ground is provided on the upper surface of the third substrate; a rectangular slot is etched on the metal ground; a microstrip line for feeding is provided on the lower surface of the third substrate; inner-layer metallized vias and outer-layer metallized vias are provided around the antenna; the inner-layer metallized vias penetrate through the second substrate and extend downward to the third substrate to form a substrate integrated waveguide back cavity; the outer-layer metallized vias penetrate through the first substrate and the second substrate and extend downward to the metal ground; the radio frequency excitation signal is fed in by the microstrip line and coupled through the rectangular slot to feed the antenna located above it.

[0007] Further, as a preferred technical solution of the present invention, the n×n metal strip lines are 2×2 metal strip lines.

[0008] Further, as a preferred technical solution of the present invention, the upper surface part of the first substrate outside the outer-layer metallized vias is subjected to printed metal treatment.

[0009] Further, as a preferred technical solution of the present invention, the rectangular slot provides a resonant mode as a radiation unit and operates in the 28 GHz band; the metal strip lines on the upper surface of the first substrate generate another resonant point and operate in the 28 GHz band; the two stacked first rectangular metal patch and the second rectangular metal patch on the upper surfaces of the first substrate and the second substrate respectively generate patch fundamental mode TM 01 Two resonant modes, and the two generated resonant points operate in the 39 GHz band.

[0010] Further, as a preferred technical solution of the present invention, the microstrip line is connected with a matching stub to improve the overall impedance matching of the hybrid antenna.

[0011] Further, as a preferred technical solution of the present invention, the antenna is expanded into a 1×N beam scanning antenna array.

[0012] For the millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning described in the present invention, compared with the prior art by adopting the above technical solutions, it has the following technical effects:

[0013] 1. The present invention can well excite the entire antenna radiation unit by using the rectangular slot.

[0014] 2. The present invention obtains two resonance modes at both 28 GHz and 39 GHz frequency bands, achieving coverage of the two 5G millimeter-wave hot frequency bands of 28 GHz and 39 GHz; the introduction of a stacked rectangular patch and a parasitic structure of a metal strip enables a low-profile overall design, and the overall profile height of the antenna of the present invention is only 1.2 mm (~0.11λ0@28 GHz).

[0015] 3. The present invention adopts a hybrid antenna scheme, mixing multiple radiation units under the same structure, with a compact structure, so it can be realized with a relatively small plane size of the radiation unit. The plane size of the radiation unit is 0.345λ1×0.345λ1 (~λ1@28 GHz).

[0016] 4. The present invention uses two layers of metallized vias around the antenna to suppress surface waves and improve the antenna gain.

[0017] 5. The antenna of the present invention has good radiation performance, with a symmetric radiation pattern and relatively small cross polarization.

[0018] 6. The present invention uses a multi-resonator hybrid antenna design scheme, with a compact structure and a relatively small plane size of the radiation unit. The plane size of the radiation unit is 0.345λ1×0.345λ1 (λ1@28 GHz), so it can be conveniently expanded into a beam scanning antenna array. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of an embodiment of the present invention Figure 1 ;

[0020] Figure 2 is a schematic structural diagram of an embodiment of the present invention Figure 2 ;

[0021] Figure 3 is a schematic structural diagram of an embodiment of the present invention Figure 3 ;;

[0022] Figure 4 is a schematic diagram of the antenna array of an embodiment of the present invention;

[0023] Figure 5 is the |S 11 | and gain simulation result diagram of the antenna unit of an embodiment of the present invention;

[0024] Figure 6 is the simulated radiation pattern of the resonance points at 24.4 GHz and 28.8 GHz of an embodiment of the present invention;

[0025] Figure 7 is the simulated radiation pattern of the resonance points at 37.6 GHz and 39.2 GHz of an embodiment of the present invention;

[0026] Figure 8 is the S-parameter simulation result diagram of the antenna array according to the embodiment of the present invention;

[0027] Figure 9 is the gain simulation result diagram of the antenna array according to the embodiment of the present invention;

[0028] Figure 10 is the beam scanning range simulation result diagram of the antenna array according to the embodiment of the present invention at 28 GHz;

[0029] Figure 11 is the beam scanning range simulation result diagram of the antenna array according to the embodiment of the present invention at 39 GHz;

[0030] In the drawings, 1. metal strip; 2. first rectangular metal patch; 3. outer metallized via; 4. first substrate; 5. second rectangular metal patch; 6. inner metallized via; 7. second substrate; 8. rectangular slot; 9. metal ground; 10. third substrate; 11. microstrip line. Detailed Embodiment

[0031] The following further explains the present invention in detail with reference to the drawings, so that those skilled in the art can understand the present invention more deeply and be able to implement it. However, the following is only used to explain the present invention by referring to examples and is not a limitation of the present invention.

[0032] As Figures 1 to 3 shown, a millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning includes a first substrate 4, a second substrate 7, and a third substrate 10 stacked on top of each other in sequence from top to bottom. There is an adhesive board between the first substrate 4 and the second substrate 7, and an adhesive board between the third substrate 7 and the fourth substrate 10; the upper surface of the first substrate 4 is printed with a first rectangular metal patch 2 and 2×2 metal strips 1 surrounding the first rectangular metal patch 2; the upper surface of the second substrate 7 is printed with a second rectangular metal patch 5; the upper surface of the third substrate 10 is provided with a metal ground 9; a rectangular slot 8 is etched on the metal ground 9; the lower surface of the third substrate 10 is provided with a microstrip line 11 for feeding; inner metallized vias 6 and outer metallized vias 3 are provided around the antenna; the inner metallized vias 6 penetrate through the second substrate 7 and extend downward to the third substrate 10 to form a substrate integrated waveguide back cavity; the outer metallized vias 3 penetrate through the first substrate 4 and the second substrate 7 and extend downward to the metal ground 9; the radio frequency excitation signal is fed into by the microstrip line 11 and feeds the antenna located above it through coupling via the rectangular slot 8.

[0033] The upper surface portion of the first substrate 4 outside the outer metallized vias 3 is subjected to printed metal treatment. The rectangular slot 8 provides a resonant mode as a radiation element operating in the 28 GHz band; the metal strip 1 on the upper surface of the first substrate 4 generates another resonant point operating in the 28 GHz band; the two stacked first rectangular metal patches 2 and the second rectangular metal patches 5 on the upper surfaces of the first substrate 4 and the second substrate 7 respectively generate patch fundamental modes TM 01 Two resonant modes, and the two generated resonant points operate in the 39 GHz band. Thus, there are two resonant points in each band, thereby achieving the working effect of millimeter-wave dual-band broadband; on this basis, matching stubs are further introduced on the microstrip line 11 to improve the overall impedance matching of the hybrid antenna.

[0034] While realizing millimeter-wave dual-band broadband coverage, the present invention can take into account the excellent characteristics of a small planar size and a low profile, can be conveniently expanded into a beam scanning antenna array, and has great practical value. As Figure 4 shown, the present invention is therefore applicable to a beam scanning antenna array, and the 1×4 array constructed based on this antenna has good beam scanning ability.

[0035] The present invention adopts a metal strip-slot-stacked rectangular patch hybrid antenna scheme. Among them, the rectangular slot 8 and the metal strip 1 provide the first and second resonant points in the 28 GHz band; the fundamental mode TM of the second rectangular metal patch 5 01 mode provides the first resonant point in the 39 GHz band, and the fundamental mode TM of the first rectangular metal patch 2 01 mode provides the second resonant point in the 39 GHz band. Therefore, there are two resonant points in both the 28 GHz band and the 39 GHz band. Then, impedance matching is performed using matching stubs with a length of approximately one-quarter wavelength to obtain a better impedance bandwidth. Finally, the present invention realizes a millimeter-wave dual-band broadband design and successfully covers millimeter-wave bands such as n257, n258, n260 bands, and n261 band.

[0036] This antenna design mainly solves the problems existing in the existing millimeter-wave dual-band antenna design, such as narrow antenna bandwidth, large planar size, and difficult individual adjustment of each band. First, a rectangular slot 8 is etched on the metal ground 9, which forms a slot coupling structure with the microstrip line 11 below the third substrate 10, and this structure can well excite the entire antenna element; secondly, two layers of metallized vias are arranged around the antenna element to suppress surface waves and improve the antenna gain.

[0037] In specific implementation, the present invention is a millimeter-wave dual-band metal strip-slot-stacked rectangular patch hybrid antenna, and the simulation software uses HFSS. The structures of its antenna element and array are as Figures 1 to 4As shown. The dielectric constant of the low-dielectric-constant dielectric substrates used for the first substrate 4, the second substrate 7, and the third substrate 10 is 3.55, and the loss tangent is 0.0027; the dielectric constant of the adhesive board between the first substrate 4, the second substrate 7, and the third substrate 10 is 3.66, and the loss tangent is 0.004. The overall cross-sectional height is 1.2 mm (~0.11λ0 @ 28 GHz), and the planar size is 0.345λ1 × 0.345λ1 (~λ1 @ 28 GHz).

[0038] The parameters of the specific antenna structure are shown in Table 1 as follows:

[0039] Table 1

[0040] Name <![CDATA[h1]]> <![CDATA[h2]]> <![CDATA[h3]]> h <![CDATA[l1]]> <![CDATA[l2]]> <![CDATA[l3]]> <![CDATA[l4]]> Dimensions (mm) 0.508 0.305 0.203 0.1 10.2 4.8 3.7 1.75 Name <![CDATA[l5]]> w k <![CDATA[d1]]> <![CDATA[d2]]> r ls <![CDATA[w s > Dimensions (mm) 1.625 0.4 0.625 0.6 0.8 0.1 1.8 0.2 Name <![CDATA[l m1 > <![CDATA[w m1 > <![CDATA[l m2 > <![CDATA[w m2 > G d Dimensions (mm) 1.63 0.8 6.48 0.45 15 4.8

[0041] The transmission response of the antenna element is as Figure 5 shown. Taking |S 11 | ≤ -10 dB as the standard, the impedance bandwidth ranges from 23.9 - 29.7 GHz (relative bandwidth is 21.75%), 36.2 - 40.6 GHz (relative bandwidth is ~11.59%). It can be seen that it well covers the four 5G millimeter-wave hotspots of n257, n258, n261, and n260, achieving wideband coverage of the millimeter-wave dual band. From the radiation response Figure 5 it can be known that the average gain within the frequency band generated by this antenna is above 7 dBi. Figure 6 is the simulated radiation pattern at 24.4 GHz, which is the slot resonance point, and at 28.8 GHz, which is the 2×2 metal strip resonance point; Figure 7 is the simulated radiation pattern at 37.6 GHz, which is the resonance point of the second rectangular metal patch 5, and at 39.2 GHz, which is the resonance point of the first rectangular metal patch 2. It can be seen from the figure that all the radiation patterns in the two millimeter-wave frequency bands of the antenna are symmetric, and the cross polarization is better than 30 dB within the 3 dB beam range.

[0042] The transmission response of the antenna array is as Figure 8 shown. Taking |S 11 | ≤ -10 dB as the standard, the impedance bandwidth ranges from 24.1 - 30.4 GHz (relative bandwidth is 23.12%), 36.52 - 40.75 GHz (relative bandwidth is ~11%). It can be seen that the 1×4 array constructed by this antenna element can still well cover the four 5G millimeter-wave hotspots of n257, n258, n261, and n260, achieving wideband coverage of the millimeter-wave dual band. From the radiation response Figure 9 it can be known that the gain of this antenna array is greater than 9.6 dBi within the 28 GHz frequency band and greater than 13 dBi within the 39 GHz frequency band. Figure 10 In, this antenna array can achieve array radiation scanning angles of θ = 0°, 25°, 50° at 28 GHz;Figure 11 In this case, the antenna array can achieve array radiation scanning angles of θ = 0°, 15°, and 30° at 39 GHz. It can be seen that the antenna proposed in this paper is applicable to beam scanning arrays. The 1×4 array constructed based on this antenna has beam scanning performances of ±50° and ±30° at 28 GHz and 39 GHz, respectively.

[0043] The present invention uses a rectangular slot 8 etched on a metal ground 9 to simultaneously excite four radiation structures of a metal strip - slot - stacked rectangular patch. Two resonance points can exist in each frequency band, achieving a broadband working effect in the two 5G millimeter - wave hot - spot frequency bands of 28 GHz and 39 GHz. The present invention adopts a stacked rectangular patch structure, so it has the characteristic of a low profile height. The overall height of the antenna is only 1.2 mm (~0.11λ1@28 GHz); by mixing multiple radiation units under the same antenna structure, it is structurally compact and can be realized with a relatively small unit planar size. The unit planar size is 0.345λ1×0.345λ1 (~λ1@28 GHz). Therefore, the present invention is applicable to beam scanning antenna arrays, and the 1×4 array constructed based on this antenna has good beam scanning capabilities.

[0044] The present invention uses a multi - resonator hybrid antenna design scheme, which is structurally compact with a relatively small radiation unit planar size. The radiation unit planar size is 0.345λ1×0.345λ1 (λ1@28 GHz). Therefore, it can be easily expanded into a beam scanning antenna array. The 1×4 array constructed based on this antenna has good beam scanning capabilities, with beam scanning performances of ±50° and ±30° at 28 GHz and 39 GHz, respectively. Compared with other millimeter - wave antenna solutions, the antenna design proposed in the present invention has the advantages of being structurally compact, having a broadband dual - band, small size, low profile, and each resonance point can be adjusted independently.

[0045] The specific implementation schemes described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above - mentioned are only specific implementation schemes of the present invention and are not used to limit the scope of the present invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A millimeter-wave dual-band multi-resonator hybrid antenna suitable for beam scanning, comprising a first substrate (4), a second substrate (7) and a third substrate (10) stacked in sequence from top to bottom. There is an adhesive plate between the first substrate (4) and the second substrate (7), and there is an adhesive plate between the second substrate (7) and the third substrate (10); characterized in that, On the upper surface of the first substrate (4), a first rectangular metal patch (2) and n×n metal strip lines (1) surrounding the first rectangular metal patch (2) are printed; on the upper surface of the second substrate (7), a second rectangular metal patch (5) is printed; on the upper surface of the third substrate (10), a metal ground (9) is provided; a rectangular slot (8) is etched on the metal ground (9); on the lower surface of the third substrate (10), a microstrip line (11) for feeding is provided; inner metallized vias (6) and outer metallized vias (3) are provided around the antenna; the inner metallized vias (6) penetrate through the second substrate (7) and extend downward to the third substrate (10) to form a substrate integrated waveguide back cavity; the outer metallized vias (3) penetrate through the first substrate (4) and the second substrate (7) and extend downward to the metal ground (9); the radio frequency excitation signal is fed in through the microstrip line (11) and coupled through the rectangular slot (8) to feed the antenna located thereon; The rectangular slot (8) provides a resonant mode as a radiation element operating in the 28 GHz band; the metal strip (1) on the upper surface of the first substrate (4) generates another resonant point operating in the 28 GHz band; two stacked first rectangular metal patches (2) and second rectangular metal patches (5) located on the upper surfaces of the first substrate (4) and the second substrate (7) respectively generate patch fundamental modes TM 01 Two resonant modes, and the two generated resonant points operate in the 39 GHz band.

2. The millimeter-wave dual-band multi-resonator hybrid antenna applicable to beam scanning according to claim 1, wherein The n×n metal strip lines (1) are 2×2 metal strip lines (1).

3. A millimeter-wave dual-band multi-resonator hybrid antenna applicable to beam scanning according to claim 1, characterized in that The upper surface portion of the first substrate (4) outside the outer metallized vias (3) is subjected to printed metal treatment.

4. A millimeter-wave dual-band multi-resonator hybrid antenna applicable to beam scanning according to claim 1, characterized in that, The microstrip line (11) is connected with a matching stub to improve the overall impedance matching of the hybrid antenna.

5. A millimeter-wave dual-band multi-resonator hybrid antenna applicable to beam scanning according to any one of claims 1 to 4, characterized in that, The antenna is extended to a 1×N beam scanning antenna array.

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